Clampitt relocated to Kansas to live with her brother's family in January 1987. She previously lived in Wichita Falls, Texas with her son. Clampitt had problems with drugs and alcohol in the early to mid-1980s. Her brother agreed to assist her and Clampitt left her child in her parents' custody in Texas while she located employment. She located an advertisement for Equi II, a management consulting firm in Overland Park, Kansas, shortly after her arrival. Her brother said that the wording in the ad, which promised extensive traveling and a new wardrobe, appeared strange. Clampitt was hired by the company's owner, John Edward Robinson Sr., shortly afterwards. A photo of Robinson is posted at the end of this case summary.

Clampitt often stayed at local hotels for several nights due to her position, but her brother became concerned for her welfare when she never returned home after leaving on June 15, 1987. He told authorities that he visited Robinson at the Equi II offices and Robinson said he was aware of his search. Clampitt has never been heard from again.

Clampitt's case was reopened in 2000 after Robinson, who has a lengthy criminal history, was charged with murdering several women in the Kansas area. Five bodies were discovered in barrels in a storage facility rented by Robinson, whose trial began in 2000. He is the main suspect in Clampitt's case. Robinson is also believed to be involved in the disappearances of Paula Godfrey and Lisa Stasi, both young women who were associated with Robinson in Overland Park in 1984 and 1985 and vanished without a trace. Lisa has never been located, but Robinson is charged with her murder. Her daughter, Tiffany, was allegedly abducted by Robinson and placed with his brother's family in an illegal adoption shortly after Lisa and the infant vanished in 1985. DNA testing confirmed Tiffany's identity in 2000.

Robinson was convicted of Lisa's murder and the murders of two additional women in Kansas in late October 2002. A jury recommended that he receive the death penalty for the other women's homicides. Robinson will be sentenced to life in prison for Lisa's murder in the near future.

Clampitt has never been located and her case remains open. Her name was initially misspelled as "Katherine Clampet" when investigators announced the reopening of her investigation, but has since been corrected.